Release: September 9, 2001

Contact: Kenneth Satterfield(703) 519-1563[email protected]303-228-8460 (9/7-9/12)

TESTING ELEVATED HIGH-FREQUENCY NOISE LEVELS PROVIDES AN INDICATOR OF NOISE-INDUCED HEARING LOSS

Denver, CO -- The National Institute on Deafness and Other Communication Disorders states that more than 30 million Americans are exposed to hazardous sound levels on a regular basis. Exposure occurs in the work place, in recreational settings and at home. Harmful noises at home may come from vacuum cleaners, garbage disposals, lawn mowers, leaf blowers and shop tools. Of the 28 million Americans who have some degree of hearing loss, about one-third have been affected, at least in part, by noise.

Noise-induced hearing loss (NIHL) is insidious in onset, not currently treatable and extremely common. Musicians believe that long-term exposure to high frequency sounds has resulted in long-term damage to their hearing. Now, two medical researchers from Scotland have demonstrated that NIHL may be detectable at an earlier stage by measuring extended high frequency thresholds.

In their study, they set out to determine the air conduction thresholds in both the conventional (CF) and extended high frequencies (EHF) in noise-exposed subjects in relationship to duration of exposure and age values. They recommend that extended high-frequency threshold measurement be included in the hearing assessment battery of patients exposed to loud, high frequency sounds. They believe that the test has good predictive value for NIHL.

The authors of "Extended High-Frequency Thresholds in Noise-Induced Hearing Loss" are Maged M F Abdelkader, FRCS, and D. Carrick, FRCS, both from Glasgow, Scotland, United Kingdom. Their findings were presented at the American Academy of Otolaryngology--Head and Neck Surgery Foundation Annual Meeting/OTO EXPO, being held September 9-12, 2001, at the Colorado Convention Center, Denver, CO.

Methods: The study subjects were airway runway personnel with inadequate ear protection and no record of organic ear pathology. Forty patients, aged 20-60 years, were selected and grouped into Group One: 20-30 years old; Group Two: 31-40 years old; Group Three 3: 41-50 years old; and Group Four: 51-60 years old. Both CF and EHF thresholds were measured.

Results: The older age groups with 20 years of exposure demonstrated elevation of EHF and CF exposure. The younger age groups did register elevated findings but not as significant as the older subjects. Despite fairly normal CF thresholds, the EHF threshold is related to the duration of exposure to noise, and it becomes more evident with advanced age.

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